My thermostat is programmed to come on at 79 degrees. It is register at 69 degrees in the house. However there is no way that temperature is correct. When we hit run it will run for a few minutes then when we look at it again it changes back to 85 degrees and the hold but is on even though we havent pushed it. We have changed the batteries. It seems to be sticking on hold... yet the temperature upstairs is way off. Any ideas why??

Brand and exact model number?

Time for a new stat